hello and questions

I'm new to SLR photography in general but surrounded by semi-professionals so I'm learning fast (usually with Canon and Nikon) but I do have a few questions.
My company works within a lot of weddings and we do nightclub style lighting along with DJ services. I'm looking into adding photography services and curious to know how the K-30 model works in *nightclub style conditions on moving targets? *(I've been googling for days looking for example shots and I'm about to scour this newly discovered forum.) I also have a will also be doing ceremony and portraiture work but I assume this camera can handle that to a fair degree. (Our services are often in the cheaper end of the market and portrait style photos I've seen from this camera still look fantastic.)

I was also looking at the k3 and k5 for the higher ISO

Any input is welcome and thanks again (I plan on having one of these 3 and uploading photos in the future!)